A light-emitting diode (hereinafter “LED”) is a semiconductor, which emits light while being electrically connected to an electric power. Due to its technical defects, the LED is employed as an indicator light in an electronic device. Recently, as an LED emitting white light, the LED is adapted for much broader and varied uses, especially for interior lighting.
When compared with a traditional light, an LED has the following advantages:
1. High energy converting efficiency in low light intensity environment. Because the LED has this advantage, the LED is widely used in low intensity back light environment, such as the back light of a mobile phone, or the back light of a television.
2. Rigid structure for better shock withstanding capability. As the LED is solid, the LED has a more rigid structure than a tungsten lamp and a fluorescent lamp for bearing shock.
3. Compact in size. The LED has so low a volume that the LED can be formed into any shape as required. For example, multiple LEDs are arranged to form an array, which provides wider applications on lighting.
4. Long life span. Although the LED is more costly than the traditional light emitting devices, the LED has a longer life span than the traditional light while being used in an environment equipped with good ventilation system.
5. Rapid reaction. The LED has a high flicker frequency.
According to the above advantages, the LED has been widely used in home lighting. In order to substitute our daily light lamp, a fluorescent lamp, for an LED lamp, the LED lamp has a structure similar to the fluorescent lamp. Such an LED lamp has two electrodes mounted on each of two sides of the LED lamp, and formed a circuit with an electric power to convert electric power into light when the two electrodes are connected to a receptacle on two sides of the LED lamp.
However, when such an LED lamp is being installed, the two electrodes are inserted into the receptacle, and other electrodes are disconnected to the receptacle purposefully. Because the electric power is still electrically connected to the LED lamp, a user working on the LED installation may touch the disconnected electrodes and suffers an electric shock.